The Sinn Féin president Gerry Adams revealed today his late father subjected family members to emotional, physical and sexual abuse.

The West Belfast MP said he discovered when he was 50 years old that his father, Gerry Adams Sr, had also abused some of his own children. He said his father was in denial for many years about his actions and eventually died a lonely old man.

Liam Adams is wanted by police over charges of abuse against his daughter over a period of several years during her childhood.

Gerry Adams urged his brother to turn himself in for the sake of his niece Aine – Liam's daughter – who has waived her legal right to anonymity.

"I was almost 50 years old and up to that point I thought we were like any other family with a loving father," he said. "It was a deep shock."

Adams said he had no recollection of being abused. He appealed for his brother to come forward and hand himself over to police.

"Aine needs justice. This has gone on for far too long. And the only way now she can get justice is through the courts," he said. "And Liam, for her sake especially, for his sake and for the sake of his other children, should do that. He should come forward."

"More important to me, Aine and her mother had to deal with all of this," he added. "But in the course of trying to deal with it I also discovered my father was an abuser.

"I don't want to distract for one second from Aine's plight. I have felt for some long time we should go public about my father as part of the healing process within my own family and to try and help other families who are in the same predicament."

Adams said the family had received professional help. There were 13 children: 10 survived and three died at birth or shortly after.

"Those who were abused didn't want to go to the police about it so in a very difficult way with everybody coming at this at different speeds and with everybody coming at it from slightly different perspectives we have with the assistance of professionals, with the assistance of other family members and friends, we have been able to survive it," he added.

He said his father was in denial for a lot of that time. "He ended up dying a very lonely man where he should have been surrounded by loving family members," he said.

"I myself for a long time wanted this to be publicised because there is a culture of concealment. But we can only do this when everybody is strong enough to do it.

"And we don't do it for any other reason than a necessary step in the healing process in our own clan. And also other families who are in the same predicament or individuals who just feel this is the end of the world.

"It obviously tests your faith in humanity when an iconic figure like my father engages in the psychological and emotional and physical and sexual abuse of a child, of his child," he added.

"But with attention, with understanding, with resolve, and with love we can find our way through all of this."

Adams was asked about his father's republican funeral and tricolour on his coffin. "Personally that was one of the great dilemmas for me because I'm a republican. I'm speaking here as a human being, as a family member," he said.

"I didn't want him buried with the tricolour. I think he besmirched it but it was a dilemma for other members of my family who felt that they didn't want this at that time out in the open."

Adams said that not being buried as a former republican activist and prisoner in the 1930s would have drawn attention to the fact that there was something wrong.

"So you have to look after the living as opposed to the dead," he said. "I always also had a view that it was going to come out at some time."